\begin{code}
module RnNames (
rnImports, importsFromLocalDecls, exportsFromAvail,
- reportUnusedNames, mkModDeps
+ reportUnusedNames, mkModDeps, main_RDR_Unqual
) where
#include "HsVersions.h"
IsBootInterface,
availName, availNames, availsToNameSet,
Deprecations(..), ModIface(..), Dependencies(..),
- GlobalRdrElt(..), unQualInScope, isLocalGRE
+ GlobalRdrElt(..), unQualInScope, isLocalGRE, pprNameProvenance
)
-import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, lookupRdrEnv,
- emptyRdrEnv, foldRdrEnv, mkRdrUnqual, isQual )
+import OccName ( varName )
+import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, lookupRdrEnv, rdrEnvToList,
+ emptyRdrEnv, foldRdrEnv, rdrEnvElts, mkRdrUnqual, isQual, mkUnqual )
import Outputable
-import Maybe ( isJust, isNothing, catMaybes )
+import Maybe ( isJust, isNothing, catMaybes, fromMaybe )
+import Maybes ( orElse, expectJust )
import ListSetOps ( removeDups )
import Util ( sortLt, notNull )
import List ( partition, insert )
-- Complains if two distinct exports have same OccName
-- Warns about identical exports.
-- Complains about exports items not in scope
-exportsFromAvail Nothing
+
+exportsFromAvail exports
+ = do { TcGblEnv { tcg_rdr_env = rdr_env,
+ tcg_imports = imports } <- getGblEnv ;
+ exports_from_avail exports rdr_env imports }
+
+exports_from_avail Nothing rdr_env
+ imports@(ImportAvails { imp_env = entity_avail_env })
= do { this_mod <- getModule ;
if moduleName this_mod == mAIN_Name then
- return []
- -- Export nothing; Main.$main is automatically exported
- else
- exportsFromAvail (Just [IEModuleContents (moduleName this_mod)])
- -- but for all other modules export everything.
+ exports_from_avail (Just [IEVar main_RDR_Unqual]) rdr_env imports
+ -- Behave just as if we'd said module Main(main)
+ -- This is particularly important if we compile module Main,
+ -- but then use ghci to call it... we jolly well expect to
+ -- see 'main'!
+ else
+ -- Export all locally-defined things
+ -- We do this by filtering the global RdrEnv,
+ -- keeping only things that are (a) qualified,
+ -- (b) locally defined, (c) a 'main' name
+ -- Then we look up in the entity-avail-env
+ return [ avail
+ | (rdr_name, gres) <- rdrEnvToList rdr_env,
+ isQual rdr_name, -- Avoid duplicates
+ GRE { gre_name = name,
+ gre_parent = Nothing, -- Main things only
+ gre_prov = LocalDef } <- gres,
+ let avail = expectJust "exportsFromAvail"
+ (lookupAvailEnv entity_avail_env name)
+ ]
}
-exportsFromAvail (Just exports)
- = do { TcGblEnv { tcg_imports = imports } <- getGblEnv ;
- warn_dup_exports <- doptM Opt_WarnDuplicateExports ;
- exports_from_avail exports warn_dup_exports imports }
-
-exports_from_avail export_items warn_dup_exports
+exports_from_avail (Just export_items) rdr_env
(ImportAvails { imp_qual = mod_avail_env,
imp_env = entity_avail_env })
= foldlM exports_from_item emptyExportAccum
exports_from_item acc@(mods, occs, avails) ie@(IEModuleContents mod)
| mod `elem` mods -- Duplicate export of M
- = warnIf warn_dup_exports (dupModuleExport mod) `thenM_`
- returnM acc
+ = do { warn_dup_exports <- doptM Opt_WarnDuplicateExports ;
+ warnIf warn_dup_exports (dupModuleExport mod) ;
+ returnM acc }
| otherwise
= case lookupModuleEnvByName mod_avail_env mod of
- Nothing -> addErr (modExportErr mod) `thenM_`
- returnM acc
+ Nothing -> addErr (modExportErr mod) `thenM_`
+ returnM acc
+
Just avail_env
- -> getGlobalRdrEnv `thenM` \ global_env ->
- let
+ -> let
mod_avails = [ filtered_avail
| avail <- availEnvElts avail_env,
- let mb_avail = filter_unqual global_env avail,
+ let mb_avail = filter_unqual rdr_env avail,
isJust mb_avail,
let Just filtered_avail = mb_avail]
-- and others, but also internally within this item. That is,
-- if 'M.x' is in scope in several ways, we'll have several
-- members of mod_avails with the same OccName.
- foldlM (check_occs warn_dup_exports ie)
- occs mod_avails `thenM` \ occs' ->
+ foldlM (check_occs ie) occs mod_avails `thenM` \ occs' ->
returnM (mod:mods, occs', avails')
exports_from_item acc@(mods, occs, avails) ie
= lookupGRE (ieName ie) `thenM` \ mb_gre ->
case mb_gre of {
- Nothing -> addErr (unknownNameErr (ieName ie)) `thenM_`
- returnM acc ;
- Just gre ->
+ Nothing -> addErr (unknownNameErr (ieName ie)) `thenM_`
+ returnM acc ;
+ Just gre ->
-- Get the AvailInfo for the parent of the specified name
- case lookupAvailEnv entity_avail_env (gre_parent gre) of {
- Nothing -> pprPanic "exportsFromAvail"
- ((ppr (ieName ie)) <+> ppr gre) ;
- Just avail ->
-
+ let
+ parent = gre_parent gre `orElse` gre_name gre
+ avail = expectJust "exportsFromAvail2"
+ (lookupAvailEnv entity_avail_env parent)
+ in
-- Filter out the bits we want
case filterAvail ie avail of {
Nothing -> -- Not enough availability
-- Phew! It's OK! Now to check the occurrence stuff!
warnIf (not (ok_item ie avail)) (dodgyExportWarn ie) `thenM_`
- check_occs warn_dup_exports ie occs export_avail `thenM` \ occs' ->
+ check_occs ie occs export_avail `thenM` \ occs' ->
returnM (mods, occs', addAvail avails export_avail)
- }}}
+ }}
-------------------------------
in_scope :: GlobalRdrEnv -> Name -> Bool
-- Checks whether the Name is in scope unqualified,
-- regardless of whether it's ambiguous or not
-in_scope env n = isJust (lookupRdrEnv env (mkRdrUnqual (nameOccName n)))
+in_scope env n
+ = case lookupRdrEnv env (mkRdrUnqual (nameOccName n)) of
+ Nothing -> False
+ Just gres -> or [n == gre_name g | g <- gres]
-------------------------------
ok_item _ _ = True
-------------------------------
-check_occs :: Bool -> RdrNameIE -> ExportOccMap -> AvailInfo -> TcRn m ExportOccMap
-check_occs warn_dup_exports ie occs avail
+check_occs :: RdrNameIE -> ExportOccMap -> AvailInfo -> TcRn m ExportOccMap
+check_occs ie occs avail
= foldlM check occs (availNames avail)
where
check occs name
= case lookupFM occs name_occ of
- Nothing -> returnM (addToFM occs name_occ (name, ie))
+ Nothing -> returnM (addToFM occs name_occ (name, ie))
+
Just (name', ie')
- | name == name' -> -- Duplicate export
- warnIf warn_dup_exports
- (dupExportWarn name_occ ie ie')
- `thenM_` returnM occs
-
- | otherwise -> -- Same occ name but different names: an error
- addErr (exportClashErr name name' ie ie') `thenM_`
- returnM occs
+ | name == name' -- Duplicate export
+ -> do { warn_dup_exports <- doptM Opt_WarnDuplicateExports ;
+ warnIf warn_dup_exports (dupExportWarn name_occ ie ie') ;
+ returnM occs }
+
+ | otherwise -- Same occ name but different names: an error
+ -> do { global_env <- getGlobalRdrEnv ;
+ addErr (exportClashErr global_env name name' ie ie') ;
+ returnM occs }
where
name_occ = nameOccName name
+
+----------------------------
+main_RDR_Unqual :: RdrName
+main_RDR_Unqual = mkUnqual varName FSLIT("main")
+ -- Don't get a RdrName from PrelNames.mainName, because
+ -- nameRdrNamegets an Orig RdrName, and we want a Qual or Unqual one.
+ -- An Unqual one will do just fine
\end{code}
%*********************************************************
-- if C was brought into scope by T(..) or T(C)
really_used_names :: NameSet
really_used_names = used_names `unionNameSets`
- mkNameSet [ gre_parent gre
- | gre <- defined_names,
- gre_name gre `elemNameSet` used_names]
+ mkNameSet [ parent
+ | GRE{ gre_name = name,
+ gre_parent = Just parent }
+ <- defined_names,
+ name `elemNameSet` used_names]
-- Collect the defined names from the in-scope environment
-- Look for the qualified ones only, else get duplicates
= acc
-- n is the name of the thing, p is the name of its parent
- mk_avail n p | n/=p = AvailTC p [p,n]
- | isTcOcc (nameOccName p) = AvailTC n [n]
- | otherwise = Avail n
+ mk_avail n (Just p) = AvailTC p [p,n]
+ mk_avail n Nothing | isTcOcc (nameOccName n) = AvailTC n [n]
+ | otherwise = Avail n
add_inst_mod m acc
| m `elemFM` acc = acc -- We import something already
= sep [ ptext SLIT("The export item") <+> quotes (ppr export_item),
ptext SLIT("attempts to export constructors or class methods that are not visible here") ]
-exportClashErr name1 name2 ie1 ie2
- | different_items
- = sep [ ptext SLIT("The export items") <+> quotes (ppr ie1)
- <+> ptext SLIT("and") <+> quotes (ppr ie2)
- , ptext SLIT("create") <+> name_msg <+> ptext SLIT("respectively") ]
- | otherwise
- = sep [ ptext SLIT("The export item") <+> quotes (ppr ie1)
- , ptext SLIT("creates") <+> name_msg ]
+exportClashErr global_env name1 name2 ie1 ie2
+ = vcat [ ptext SLIT("Conflicting exports for") <+> quotes (ppr occ) <> colon
+ , ppr_export ie1 name1
+ , ppr_export ie2 name2 ]
where
- name_msg = ptext SLIT("conflicting exports for") <+> quotes (ppr name1)
- <+> ptext SLIT("and") <+> quotes (ppr name2)
- different_items -- This only comes into play when we have a single
- -- 'module M' export item which gives rise to conflicts
- = case (ie1,ie2) of
- (IEModuleContents m1, IEModuleContents m2) -> m1 /= m2
- other -> True
+ occ = nameOccName name1
+ ppr_export ie name = nest 2 (quotes (ppr ie) <+> ptext SLIT("exports") <+>
+ quotes (ppr name) <+> pprNameProvenance (get_gre name))
+
+ -- get_gre finds a GRE for the Name, in a very inefficient way
+ -- There isn't a more efficient way to do it, because we don't necessarily
+ -- know the RdrName under which this Name is in scope. So we just
+ -- search linearly. Shouldn't matter because this only happens
+ -- in an error message.
+ get_gre name
+ = case [gre | gres <- rdrEnvElts global_env,
+ gre <- gres,
+ gre_name gre == name] of
+ (gre:_) -> gre
+ [] -> pprPanic "exportClashErr" (ppr name)
dupDeclErr (n:ns)
= vcat [ptext SLIT("Multiple declarations of") <+> quotes (ppr n),
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